Magnetic tape recording apparatus and method, magnetic tape playback apparatus and method, format for magnetic tape, and storage medium product

ABSTRACT

Pictures in number indicated by a value (3 in one example) of M in a GOP structure are set as one unit. AUX data (denoted by U in FIG.  32 ) related to those pictures, audio data (denoted by A in FIG.  32 ) corresponding to those pictures, and AUX data (denoted by X in FIG.  32 ) related to the audio data are arranged together at the head of 16 tracks that undergo interleaving. Subsequent to those data, one unit of pictures (3 pictures in one example) is arranged. An HD video signal and an HD audio signal can be recorded and played back with certainty.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a magnetic tape recordingapparatus and method, a magnetic tape playback apparatus and method, aformat for a magnetic tape, and a storage medium product. Moreparticularly, the present invention relates to a magnetic tape recordingapparatus and method, a magnetic tape playback apparatus and method, aformat for a magnetic tape, and a storage medium product, which enablehigh-definition video data to be recorded on or played back from themagnetic tape.

[0003] 2. Description of the Related Art

[0004] Recently, with the progress of compression technology, videodata, etc. have also been compressed by the DV (Digital Video)technique, for example, and recorded on a magnetic tape. A format forsuch compression of video data, etc. is specified as a DV format forconsumer-oriented digital video cassette recorders.

[0005]FIG. 1 illustrates a construction of one track in a conventionalDV format. In the DV format, video data is recorded after beingsubjected to the 24-25 conversion. The number of bits denoted by eachnumeral in FIG. 1 represents a value after being subjected to the 24-25conversion.

[0006] A region corresponding to a contact angle of 174 degrees of amagnetic tape around a rotary magnetic head provides an effective regionof one track. Outside the region of one track, an overwrite margin witha length of 1250 bits is formed. The overwrite margin serves to preventdata from remaining after being erased.

[0007] When the rotary head is rotated in sync with frequency of60×1000/1001 Hz, the region of one track has a length of 134975 bits,and when the rotary head is rotated in sync with frequency of 60 Hz, ithas a length of 134850 bits.

[0008] An ITI (Insert and Track Information) sector, an audio sector, avideo sector, and a subcode sector are arranged in one tracksuccessively in the trace direction of the rotary head (i.e., in thedirection from left toward right in FIG. 1). A gap G1 is formed betweenthe ITI sector and the audio sector, a gap G2 is formed between theaudio sector and the video sector, and a gap G3 is formed between thevideo sector and the subcode sector.

[0009] The ITI sector has a length of 3600 bits, and a preamble of 1400bits is arranged at the head of the ITI sector to produce a clock.Subsequent to the ITI sector, an SSA (Start Sync Area) and a TIA (TrackInformation Area) are arranged in length of 1920 bits in this order. Abit train (sync number) necessary for detecting the position of the TIAis arranged in the SSA. Information indicating that video data is in theDV format for consumer-oriented equipment, information indicatingwhether the mode is an SP or LP mode, information indicating a patternof a pilot signal of one frame, etc. are recorded in the TIA. Subsequentto the TIA, a postamble of 280 bits is arranged.

[0010] The gap G1 has a length of 625 bits.

[0011] The audio sector has a length of 11550 bits. At the head and endof the audio sector, 400 bits and 500 bits are used for a preamble and apostamble, respectively, and 10650 bits between the preamble and thepostamble are used for data (audio data).

[0012] The gap G2 has a length of 700 bits.

[0013] The video sector has a length of 113225 bits. At the head and endof the video sector, 400 bits and 925 bits are used for a preamble and apostamble, respectively, and 111900 bits between the preamble and thepostamble are used for data (video data).

[0014] The gap G3 has a length of 1550 bits.

[0015] The subcode sector has a length of 3725 bits when the rotary headis rotated at frequency of 60×1000/1001 Hz, and has a length of 3600bits when the rotary head is rotated at frequency of 60 Hz. At the headand end of the subcode sector, 1200 bits are used for a preamble and1325 bits (when the rotary head is rotated at frequency of 60×1000/1001Hz) or 1200 bits (when the rotary head is rotated at frequency of 60 Hz)are used for a postamble, respectively, and 1200 bits between thepreamble and the postamble are used for data (subcode).

[0016] In the conventional DV format, as described above, not only thegaps G1 to G3 are formed between adjacent two of the ITI sector, audiosector, video sector and the subcode sector, but also the preamble andthe postamble are provided for each sector. Therefore, the conventionalDV format has a drawback that it includes a relatively large amount ofso-called overhead and hence cannot provide a sufficiently high level ofrecording rate for effective data.

[0017] Such a drawback leads to a problem as follows. When recordinghigh-definition video data (hereinafter referred to as HD video data),for example, a bit rate of about 25 Mbps is required. However, a bitrate obtained in the conventional DV format by MP@HL in accordance withMPEG (Moving Picture Expert Group) is about 22 Mbps at maximum exceptfor search video data. As a result, although the conventional DV formatcan record standard-definition video data (hereinafter referred to as SDvideo data), but it cannot ensure a satisfactory level of image qualitywhen the HD video data is compressed and recorded by MP@HL or MP@H-14.

SUMMARY OF THE INVENTION

[0018] In view of the state of the art set forth above, it is an objectof the present invention to enable HD video data to be recorded on andplayed back from a magnetic tape.

[0019] A magnetic tape recording apparatus according to the presentinvention comprises a first acquiring unit for acquiring video data,audio data or search data; a second acquiring unit for acquiringauxiliary data having a variable length and related to the data acquiredby the first acquiring unit; a selecting unit for selecting, as firstgroup data, one of the data acquired by the first acquiring unit and thedata acquired by the second acquiring unit; a third acquiring unit foracquiring second group data containing a subcode related to the firstgroup data; a merging unit for merging the first group data and thesecond group data such that the first group data and the second groupdata are continuously arranged on tracks of a magnetic tape withoutbeing spaced away from each other; and a supplying unit for supplyingdata merged by the merging unit to a rotary head to record the mergeddata on the magnetic tape.

[0020] The first acquiring unit may acquire, as the first group data,the video data in edit units.

[0021] Preferably, the second acquiring unit acquires, as the secondgroup data, auxiliary data related to the audio data and auxiliary datarelated to the video data; and the merging unit merges the auxiliarydata related to the audio data, the audio data, the auxiliary datarelated to the video data, and the video data to be arranged in thisorder.

[0022] The second acquiring unit may further acquire auxiliary datarequired for pre-playback; and the merging unit may merge the auxiliarydata required for pre-playback to be arranged at the head of an editunit of the video data.

[0023] Preferably, the auxiliary data required for pre-playback includesthe contents recorded in a subcode sector.

[0024] A magnetic tape recording method according to the presentinvention comprises a first acquiring step of acquiring video data,audio data or search data; a second acquiring step of acquiringauxiliary data having a variable length and related to the data acquiredby processing in the first acquiring step; a selecting step ofselecting, as first group data, one of the data acquired by processingin the first acquiring step and the data acquired by processing in thesecond acquiring step; a third acquiring step of acquiring second groupdata containing a subcode related to the first group data; a mergingstep of merging the first group data and the second group data such thatthe first group data and the second group data are continuously arrangedon tracks of a magnetic tape without being spaced away from each other;and a supplying step of supplying data merged by processing in themerging step to a rotary head to record the merged data on the magnetictape.

[0025] A storage medium product according to the present inventionstores a computer-readable program comprising a first acquiring step ofacquiring video data, audio data or search data; a second acquiring stepof acquiring auxiliary data having a variable length and related to thedata acquired by processing in the first acquiring step; a selectingstep of selecting, as first group data, one of the data acquired byprocessing in the first acquiring step and the data acquired byprocessing in the second acquiring step; a third acquiring step ofacquiring second group data containing a subcode related to the firstgroup data; a merging step of merging the first group data and thesecond group data such that the first group data and the second groupdata are continuously arranged on tracks of a magnetic tape withoutbeing spaced away from each other; and a supplying step of supplyingdata merged by processing in the merging step to a rotary head to recordthe merged data on the magnetic tape.

[0026] In a format for a magnetic tape according to the presentinvention, first group data comprising video data, audio data or searchdata, or comprising auxiliary data having a variable length and relatedto the video data, the audio data or the search data, and second groupdata containing a subcode related to the video data, the audio data orthe search data are recorded such that the first group data and thesecond group data are continuously arranged on tracks of the magnetictape without being spaced away from each other.

[0027] With the magnetic tape recording apparatus, the magnetic taperecording method, and the storage medium product storing thecomputer-readable program according to the present invention, videodata, audio data or search data is acquired, and auxiliary data having avariable length and related to the acquired data is acquired. One ofthese two types of acquired data is selected as first group data, andsecond group data containing a subcode related to the first group datais acquired. The first group data and the second group data are mergedsuch that the first group data and the second group data arecontinuously arranged on tracks of a magnetic tape without being spacedaway from each other. Merged data is recorded on the magnetic tape.

[0028] A magnetic tape playback apparatus according to the presentinvention comprises an acquiring unit for acquiring auxiliary data, asfirst group data, having a variable length and related to compressedhigh-definition or standard-definition video data, audio data or searchdata, or second group data containing a subcode related to the firstgroup data; and a decompressing unit for decompressing the compressedhigh-definition video data, which is contained in data reproduced from amagnetic tape with a rotary head, by using the auxiliary data or thesecond group data acquired by the acquiring unit.

[0029] A magnetic tape playback method according to the presentinvention comprises an acquiring step of acquiring auxiliary data, asfirst group data, having a variable length and related to compressedhigh-definition or standard-definition video data, audio data or searchdata, or second group data containing a subcode related to the firstgroup data; and a decompressing step of decompressing the compressedhigh-definition video data, which is contained in the data reproducedfrom a magnetic tape with a rotary head, by using the auxiliary data orthe second group data acquired by processing in the acquiring step.

[0030] A storage medium product according to the present inventionstores a computer-readable program comprising an acquiring step ofacquiring auxiliary data, as first group data, having a variable lengthand related to compressed high-definition or standard-definition videodata, audio data or search data, or second group data containing asubcode related to the first group data; and a decompressing step ofdecompressing the compressed high-definition video data, which iscontained in data reproduced from a magnetic tape with a rotary head, byusing the auxiliary data or the second group data acquired by processingin the acquiring step.

[0031] With the magnetic tape playback apparatus, the magnetic tapeplayback method, and the storage medium product storing thecomputer-readable program according to the present invention, auxiliarydata, as first group data, having a variable length and related tocompressed high-definition or standard-definition video data, audio dataor search data, or second group data containing a subcode related to thefirst group data is acquired. The compressed high-definition video data,which is contained in data reproduced from a magnetic tape with a rotaryhead, is decompressed by using the acquired auxiliary data or secondgroup data.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032]FIG. 1 is a representation for explaining an arrangement of tracksectors in a conventional DV format;

[0033]FIG. 2 is a block diagram showing one example of construction of arecording system of a magnetic tape recording/playback apparatusaccording to the present invention;

[0034]FIG. 3 is a representation for explaining a format of tracksformed on a magnetic tape shown in FIG. 2;

[0035]FIG. 4 is a chart for explaining a pilot signal for trackingcontrol recorded in one track shown in FIG. 3;

[0036]FIG. 5 is a chart for explaining another pilot signal for trackingcontrol recorded in another track shown in FIG. 3;

[0037]FIG. 6 is a chart for explaining still another pilot signalrecorded in still another track shown in FIG. 3;

[0038]FIG. 7 is a representation for explaining a sector arrangementwithin each track shown in FIG. 3;

[0039]FIG. 8 is a representation for explaining patterns of a preambleand a postamble shown in FIG. 7;

[0040]FIG. 9 is a representation for explaining a structure of a mainsector shown in FIG. 7;

[0041]FIGS. 10A and 10B are representations for explaining a main sectorID shown in FIG. 9;

[0042]FIG. 11 is a representation for explaining an SB header of themain sector shown in FIG. 9;

[0043]FIG. 12 shows data representing a search data;

[0044]FIG. 13 shows data representing types of AUX data;

[0045]FIG. 14 is a table for explaining system data having a fixedlength;

[0046]FIG. 15 is a table for explaining system data having a variablelength;

[0047]FIGS. 16A, 16B, 16C and 16D are representations for explainingformats of system data having a fixed length;

[0048]FIGS. 17A, 17B, 17C and 17D are representations for explainingformats of system data having a variable length; FIGS. 18A and 18B aretables for explaining information defined in a header section;

[0049]FIG. 19 is another representation for explaining the format of thesystem data having a fixed length;

[0050]FIG. 20 is another representation for explaining the format of thesystem data having a variable length;

[0051]FIG. 21 is a representation for explaining average values of datarecorded in the main sector;

[0052]FIG. 22 is a representation for explaining a structure of asubcode sector shown in FIG. 7;

[0053]FIG. 23 is a table for explaining a subcode sync block ID;

[0054]FIGS. 24A and 24B are representations for explaining subcode data;

[0055]FIG. 25 is another representation for explaining the conventionalDV format;

[0056]FIG. 26 is a table for explaining tape position information;

[0057]FIG. 27 is a representation for explaining an EPO;

[0058]FIG. 28 is a table for explaining an ECCTB;

[0059]FIG. 29 shows data for an audio mode;

[0060]FIG. 30 shows data for a video mode;

[0061]FIG. 31 is a table for explaining DATA-H;

[0062]FIG. 32 is a representation for explaining data in a recordedstate;

[0063]FIG. 33 is a representation for explaining a process for detectinga main sector corresponding to a subcode sector;

[0064]FIG. 34 is a table for explaining the AUX data;

[0065]FIG. 35 is another representation for explaining a process fordetecting a main sector corresponding to a subcode sector; and

[0066]FIG. 36 is a block diagram showing one example of construction ofa playback system of the magnetic tape recording/playback apparatusaccording to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0067]FIG. 2 shows one example of construction of a recording system ofa magnetic tape recording/playback apparatus to which the presentinvention is applied. A video data compressing unit 1 compresses aninputted HD video signal by, e.g., MP@HL or MP@H-14 in accordance withMPEG.

[0068] An audio data compressing unit 2 compresses an audio signal,which corresponds to the HD video signal, by an audio compression methodin accordance with MPEG1 layer2 or AAC, for example. The audio signal iscompressed to a rate of 256 Kbps to 384 Kbps by the audio datacompressing unit 2.

[0069] System data made up of AUX (auxiliary) data, subcode data, etc.is inputted to a terminal 3 from a controller 13. The system datacontains data representing text information externally inputted asadditional data, associated with the video and audio signals, toindicate the copyright, shooting situation, etc., a title time code(TTC) for assisting a search, editing, etc., track position information,apparatus setting information, and so on.

[0070] A switch 4 is changed over by the controller 13 to select anoutput of the video data compressing unit 1, an output of the audio datacompressing unit 2, or the system data supplied through the terminal 3at the predetermined timing for supply to an error code and ID addingunit 5.

[0071] The error code and ID adding unit 5 adds an errordetecting/correcting code and an ID to the data inputted through theswitch 4, and carries out an interleaving process among 16 tracks.Resulting data is outputted to a 24-25 converter 6.

[0072] The 24-25 converter 6 adds redundant one bit, which is selectedto enhance components of a pilot signal for tracking so as to appear ata higher level, for converting the inputted data in units of 24 bitsinto data in units of 25 bits.

[0073] A sync generator 7 generates sync data and amble data that areadded to main data (FIG. 9) and subcode data (FIG. 22) described later.

[0074] A switch 8 is controlled by the controller 13 to select one of anoutput of the 24-25 converter 6 and an output of the sync generator 7for outputting to a modulator 9.

[0075] The modulator 9 modulates the data inputted through the switch 8by a method (which is the same as that used for the conventional DVformat) suitable for recording on a magnetic tape 21, and suppliesmodulated data to a parallel/serial (P/S) converter 10.

[0076] The parallel/serial converter 10 converts the inputted paralleldata into serial data.

[0077] An amplifier 11 amplifies the data inputted from theparallel/serial converter 10 and supplies amplified data to a rotaryhead 12, which is attached to and rotated by a rotary drum (not shown),for recording of the data on the magnetic tape 21.

[0078]FIG. 3 represents a format of tracks formed on the magnetic tape21 by the rotary head 12. The rotary head 12 traces the magnetic tape 21in the direction from lower right toward upper left as viewed in thedrawing, whereby tracks inclined relative to the lengthwise direction ofthe magnetic tape 21 are formed. The magnetic tape 21 travels in thedirection from right toward left as viewed in the drawing.

[0079] Each track is formed as one of F0, F1 and F2 depending on thetype of pilot signal for tracking control, which is recorded in thetrack. The tracks are formed in the order of F0, F1, F0, F2, F0, F1, F0and F2.

[0080] The track F0 records therein, as shown in FIG. 4, no pilotsignals of frequency f1 and f2. The track F1 records therein, as shownin FIG. 5, the pilot signal of frequency f1. The track F2 recordstherein, as shown in FIG. 6, the pilot signal of frequency f2.

[0081] The frequencies f1, f2 are set respectively to values that are{fraction (1/90)} and {fraction (1/60)} of the recording frequency ofchannel bits.

[0082] As shown in FIG. 4, the depth of notches at the frequencies f1,f2 in the track F0 is set to 9 dB. On the other hand, as shown in FIG. 5or FIG. 6, the CNR (Carrier to Noise Ratio) of the pilot signal offrequency f1 or f2 is set to a value larger than 16 dB but smaller than19 dB. Further, the depth of notches at the frequencies f1, f2 in thetrack F1 or F2 is set to a value larger than 3 dB.

[0083] A track pattern having such frequency characteristics is similarto that in the case of using the conventional DV format. A recordingrate is about 40 Mbps, i.e., 300 tracks per second. Accordingly, amagnetic tape, a rotary head, a driving system, a demodulation system,and a control system of a consumer-oriented digital video cassetterecorder can be used, as they are, in this embodiment.

[0084] Track pair numbers are set to tracks. Each track pair number isassigned for each track pair, i.e., two tracks which are scanned at atime by two heads having a positive azimuth and a negative azimuth.Track pair numbers from 0 to 31 are assigned in an example of FIG. 3.The track pair number 0, 8, 16 or 24 is set to the track pair at thehead of every 16 tracks which undergoes interleaving (although the trackpairs to be assigned with the numbers 16 and 24 are not shown).

[0085]FIG. 7 shows one example of a sector format (sector arrangement)within each track. In FIG. 7, the number of bits indicating the lengthof each sector or section is represented by the length after beingsubjected to the 24-25 conversion. One track has a length of 134975 bitswhen the rotary head 12 is rotated at frequency of 60×1000/1001 Hz, andhas a length of 134850 bits when it is rotated at frequency of 60 Hz.The length of one track corresponds to a contact angle of 174 degrees ofthe magnetic tape 21 around the rotary head 12. Subsequent to one track,an overwrite margin of 1250 bits is formed. The overwrite margin servesto prevent data from remaining after being erased.

[0086] In FIG. 7, the rotary head 12 traces the track in the directionfrom left toward right. A preamble of 1800 bits is arranged at the headof the track. Data in combination of a pattern A and a pattern B shownin FIG. 8, by way of example, which are required to produce a clock, isrecorded in the preamble. In the pattern A and the pattern B, values 0and 1 are reversed between them. By properly combining those patterns, atracking pattern for each of the tracks F0, F1 and F2, shown in FIGS. 4to 6, can be obtained. Note that run patterns in FIG. 8 representpatterns resulted after the 24-25 conversion executed by the 24-25converter 6 in FIG. 2.

[0087] Subsequent to the preamble of 1800 bits, a main sector with alength of 130425 bits is arranged. FIG. 9 shows a structure of the mainsector. The main sector is subjected to normal playback and searchplayback.

[0088] As shown in FIG. 9, the main sector is made up of 141 sync blockseach having a length of 888 bits (111 bytes).

[0089] Of 141 sync blocks, 123 sync blocks each comprise a 16-bit sync,24-bit ID, 8-bit sync block (SB) header, 760-bit main data, and an80-bit parity C1.

[0090] The sync is generated by the sync generator 7.

[0091] The ID is made up of, as shown in FIG. 10A, three IDs, i.e., ID0to ID2, each having a length of 1 byte.

[0092] Of b7-b0 of ID0, b7-b5 define the format type of the track, andb4-b0 define the track pair number.

[0093] In addition to the type shown in FIG. 7, the track format may beof, for example, the type wherein another ITI sector is further providedand the main sector is made up of 139 sync blocks, or the type whereinanother ITI sector and an after-recording sector comprising 7 syncblocks are further provided and the main sector is made up of 129 syncblocks. Stated otherwise, an ID or the like for identifying the type ofusable format is allocated to b7-b5 of ID0. By thus arranging the ID toidentify the type of track format, it is possible to execute ademodulation process adapted for the type of each format, and toreproduce data in an appropriate manner.

[0094] The sync block number is allocated to ID1.

[0095] Information indicating whether the data recorded in the mainsector is newly recorded one (i.e., data recorded for the first time ina vacant state) or overwritten one (i.e., data recorded on previouslyrecorded data) is allocated to ID2 as one byte of overwrite protect. Inthe case of overwriting, for example, if underlying data remains due to,e.g., instantaneous clogging of the head, newly recorded data iscorrected (erroneously corrected) based on the parity C1. To preventsuch erroneous correction, the newly recorded data and the overwrittendata are distinguished with the byte of overwrite protect. If theunderlying data is determined as being remained, it is possible to makeall of the relevant sync blocks invalid (handle them as a burst error)and carry out erasure correction based on a parity C2.

[0096]Fig. 10B shows ID0 to ID2 contained in each of the 141 syncblocks. ID0 to ID2 are added by the error code and ID adding unit 5.

[0097] As shown in FIG. 11, the SB header comprises 8 bits of b7-b0. Ofb7-b0, b7-b5 set a predetermined value indicating the type of main data(such as audio data, video data, search video data, transport streamdata, and AUX data), and b4-b0 set a predetermined value indicatingdetails of the main data.

[0098] A value 0 of b7-b5 indicates that the main data is video data(PES video data) in a PES (Program Elementary Stream) format inaccordance with MPEG2. A value 1 of b7-b5 indicates that the main datais audio data (PES audio data) in the PES format. In this case, dataindicating whether the data (video or audio data) is partial (less than95 bytes) or full (95 bytes) is allocated to b4 of b4-b0, and dataindicating a counted value is allocated to b3-b0.

[0099] A value 2 of b7-b5 indicates that the main data is search data.In this case, data indicating whether the search data is video or audiodata is allocated to b4 of b4-b0, and data indicating a search speed isallocated to b3-b1. As shown in FIG. 12, by way of example, a value 1 ofb3-b1 indicates a 4-time speed; a value 2 indicates an 8-time speed; avalue 4 indicates a 16-time speed; and a value 5 indicates a 32-timespeed. Additionally, by designing the rotary head (drum) to rotate at aspeed in a following manner, a search can be performed with a widerrange of adaptable speed for each multiple speed (corresponding to thedrum rotational speed). Furthermore, the search video data is a low-bitrate data resulting from omitting high-frequency components of an Ipicture.

[0100] Returning to FIG. 11, a value 3 of b7-b5 indicates that the maindata is AUX (auxiliary) data. In this case, data indicating the type(AUX mode) of AUX data is allocated to b4-b2 of b4-b0, by way ofexample, as shown in FIG. 13.

[0101] More specifically, a value 1 of b4-b2 indicates that the AUX datais related to the PES video data (AUX-V in FIG. 11), and a value 1indicates that the AUX data is related to the PES audio data (AUX-A). Avalue 2 indicates that the AUX data is PSI (Program SpecificationInformation) (PES-PSI1) corresponding to the first half of the datarecorded in a transport stream format, and a value 3 indicates that theAUX data is PSI (PES-PSI2) corresponding to the second half of thoserecorded data. A value 4 indicates that the AUX data is any ofpredetermined data (called system data; System), shown in FIGS. 14 and15, for each of which a keyword number is set. Though described later inmore detail, FIG. 14 represents the system data fixed in data amount andFIG. 15 represents the system data variable in data amount.

[0102] Returning to FIG. 11 again, a value 4 of b7-b5 indicates that themain data corresponds to the first half of the data recorded in thetransport stream format. In this case, a jump flag is allocated to b4and b3, and a time stamp is allocated to b2-b0. A value 5 of b7-b5indicates that the main data corresponds to the second half of the datarecorded in the transport stream format. In this case, a counted valueis allocated to b4-b0.

[0103] A value 6 of b7-b5 indicates that no data is recorded as the maindata, i.e., it represents NULL. NULL is inserted when an average totalamount of main data is less than the recording-enable rate. For example,if the rate is 20 Mbps when recorded in the transport stream format,NULL is inserted in amount of about 5 Mbps.

[0104] The above-described data of the SB header is supplied from thecontroller 13 through the terminal 3.

[0105] The main data recorded in the main sector is the video datasupplied from the video data compressing unit 1, or the audio datasupplied from the audio data compressing unit 2, and the AUX data(system data) supplied from the controller 13 through the terminal 3.

[0106] A packet structure of the system data (i.e., the AUX datarecorded as the main data in the main sector with a value 3 being set tob7-b5 of the SB header and a value 0 (AUX-V), a value 1 (AUX-A) or avalue 4 (System) being set to b4-b2, as well as in a data section of asubcode sector) will now be described.

[0107] When the system data has a fixed length as shown in FIG. 14, itcomprises a header section (keyword of 1 byte) including the keywordnumber, etc., and a data section (with a fixed length (4 bytes)) forstoring the system data corresponding to the keyword number, as shown inFIG. 16A. Also, when the system data has a variable length as shown inFIG. 15, it comprises a header section (keyword of 1 byte), a datalength section (1 byte) indicating the data length, and a data section(with a variable length (n bytes)), as shown in FIG. 17A.

[0108] Further, in this embodiment, plural sets of system data may berecorded in the main sector. In such a case, a plurality of headsections are provided as shown in FIGS. 16B to 16D when the length ofthe system data is fixed, and they are provided as shown in FIGS. 17B to17D when the length of the system data is variable.

[0109] Of 1 byte of each header section (8 bits of b7-b0), b7 setstherein data indicating whether another subsequent header sectionfollows to the relevant one. More specifically, a value 0 is set in b7of each header section, following which no header section is arranged,such as a header section F1 (FIG. 16A), header section F12 (FIG. 16B),header section F23 (FIG. 16C) and a header section Fk (FIG. 16D) shownin examples of FIG. 16, or a header section X1 (FIG. 17A), headersection X12 (FIG. 17B), header section X23 (FIG. 17C) and a headersection Xk (FIG. 17D) shown in examples of FIG. 17.

[0110] On the other hand, a value 1 is set in b7 of each header section,following which another header section is arranged, such as a headersection F11, header sections F12, F22 and header sections F31, etc.(except for the header section Fk) shown in the examples of FIG. 16, ora header section X11, header sections X21, X22 and header sections X31,etc. (except for the header section Xk) shown in the examples of FIG.17.

[0111] Further, data allocated to b6-b0 of b7-b0 of each header sectiondiffer between the header section arranged at the head (such as theheader sections F1, F11, F21 and F31 shown in the examples of FIG. 16,or the header sections X1, X11, X21 and X31 shown in the examples ofFIG. 17) and the other header sections arranged in second and subsequentpositions (such as the header sections F12, F22, F23 and F32-Fk shown inthe examples of FIG. 16, or the header sections X12, X22, X23 and X32-Xkshown in the examples of FIG. 17).

[0112] Of b6-b0 of each header section arranged at the head, b6 setstherein data indicating whether the length of the system data is fixedor variable. More specifically, a value 0 indicating the length of thesystem data being fixed is set in b6 of the header section F1, headersection F11, header section F21 and the header section F31 shown in theexamples of FIG. 16, and a value 1 indicating the length of the systemdata being variable is set in b6 of the header section X1, headersection X11, header section X21 and the header section X31 shown in theexamples of FIG. 17.

[0113] In the remaining b5-b0 of each header section arranged at thehead, any of the keyword numbers (0 to 63) shown in FIG. 14, i.e., onekeyword number of the system data having a fixed length, is set.

[0114] On the other hand, in b6-b0 of each of the header sectionsarranged at the second and subsequent positions, any of the keywordnumbers (64 to 127) shown in FIG. 15, i.e., one keyword number of thesystem data having a variable length, is set.

[0115]FIG. 18 shows collectively the above-described data allocated inthe header section arranged at the head (FIG. 18A) and the headersections arranged at the second and subsequent positions (FIG. 18B).

[0116]FIGS. 19 and 20 represent, in the bit-array form, the system datahaving a fixed length (FIGS. 14 and 16) and the system data having avariable length (FIGS. 15 and 17), respectively.

[0117] Note that the above-described system data is also recorded assubcode data in the subcode sector described later.

[0118] The parity C1 (FIG. 9) is calculated by the error code and IDadding unit 5 from the ID, SB header and the main data for each syncblock, and then added.

[0119] Of 141 sync blocks, 18 sync blocks are used for the sync, ID,parity C2, and the parity C1. The parity C2 is obtained by calculatingthe SB header or the main data in the vertical direction in FIG. 9. Thiscalculation is executed in the error code and ID adding unit 5. By soselecting 18 sync blocks, a percentage of the number of sync blocks ofthe parity C2 with respect to the total number (141) of sync blocks isgiven by 12.7% (=18/141). This value is larger than the percentage(12.5% (=2 tracks/16 tracks)) that is required to develop the abilityfor correcting a continuous error over two or more tracks.

[0120]FIG. 21 shows average values of the AUX data, video data, audiodata, search data, parity C1, and the parity C2 recorded as the maindata before the 24-25 conversion.

[0121] More specifically, the average values of the numbers of syncblocks constituting the AUX data, video data, audio data, and the searchdata are respectively 7.5, 113, 1.75 and 7.5. Thus, bit rates of thesedata in average are given as follows: $\begin{matrix}{{{AUX}\quad {data}} = {95\quad {bytes} \times 0.75\quad {SB} \times 300\quad {tracks}\quad \times 8\quad {bits}}} \\{= {171\quad {kbps}}}\end{matrix}$ $\begin{matrix}{{{video}\quad {data}} = {95\quad {bytes} \times 113\quad {SB} \times 300\quad {tracks} \times 8\quad {bits}}} \\{= {25.764\quad {Mbps}}}\end{matrix}$ $\begin{matrix}{{{audio}\quad {data}} = {95\quad {bytes} \times 1.75\quad {SB} \times 300\quad {tracks}\quad \times 8\quad {bits}}} \\{= {339\quad {kbps}}}\end{matrix}$ $\begin{matrix}{{{search}\quad {data}} = {95\quad {bytes} \times 7.5\quad {SB} \times 300\quad {tracks}\quad \times 8\quad {bits}}} \\{= {1710\quad {kbps}}}\end{matrix}$

[0122] Eventually, a total bit rate is given by 28.044 (=171 kbps+25.764Mbps+339 kbps+1710 kbps) Mbps, and this rate is sufficient to record theHD video data, audio compressed data, AUX data, and the search videodata by MP@HL or MP@H-14. Note that 95 bytes mean the data amount of theSB header and the main data in one sync block.

[0123] Subsequent to the main sector, a subcode sector (FIG. 7) of 1250bits is arranged. FIG. 22 shows a structure of the subcode sector.

[0124] The subcode sector in one track has a length of 1250 bits (interms of a value after the 24-25 conversion) and comprises 10 subcodesync blocks.

[0125] One subcode sync block is made up of a sync of 16 bits, ID of 24bits, subcode data of 40 bits, and a parity of 40 bits. Thus, the lengthof one subcode sync block is 120 bits (in terms of a value before the24-25 conversion), which is about {fraction (1/7)} of the length (888bits) of one sync block of the main sector described above. By settingthe data length of the subcode sync block to be so short, the contentsof the subcode sync blocks can be surely read even with high-speedplayback on the order of 200-time speed, and therefore a high-speedsearch can be performed.

[0126] The sync in the subcode sector differs from the sync added to themain sector so that the main sector and the subcode sector may bedistinguished based on such a difference in the sync. The sync in thesubcode sector is added by the sync generator 7 in FIG. 2.

[0127] The sync block ID is made up of, as shown in FIG. 23A, three IDs,i.e., ID0 to ID2, each having a length of 1 byte.

[0128] As with ID0 in the main sector of FIG. 10A, ID0 defines theformat type and the track pair number.

[0129] Of b7-b0 of ID1, b3-b0 define the subcode sync block number, andb7-b4 are reserved bits.

[0130] The sync block number is one of numbers 0-9 that are assignedrespectively to 10 subcode sync blocks contained in the subcode sectorof one track.

[0131] As with ID2 in the main sector, one byte of overwrite protect isallocated to ID2. In the subcode sector, if ID2 indicates that therecorded data is underlying one, the processing is executed after makingall of the sync blocks invalid (i.e., on a judgment that all of the syncblocks have not been acquired).

[0132]FIG. 23B shows ID0-ID2 contained in the 10 subcode sync blocks.These ID0-ID2 are added by the error code and ID adding unit 5.

[0133] The subcode data arranged subsequent to the subcode sync block IDis the system data having a fixed length shown in FIG. 14. In otherwords, the subcode data is recorded in the form as shown in FIGS. 16 and19. Further, the type of subcode data differs between a user tape andthe so-called Pre-REC tape. In the case of a user tape, as shown in FIG.24A, the tape position information (ATNF), title time code (TTC),recording date, and the recording time are recorded as the subcode data.In the case of a Pre-REC tape, as shown in FIG. 24B, the tape positioninformation (ATNF), title time code (TTC), part number, and the chapterstart position are recorded as the subcode data. Stated otherwise, in aPre-REC tape, the part number and the chapter start position areincluded in the subcode data respectively in place of the recording dateand the recording time in a user tape.

[0134] The subcode data is supplied from the controller 13 through theterminal 3 shown in FIG. 2.

[0135]FIG. 25 shows a data structure of the subcode sync ID and thesubcode data in the conventional DV format. As seen from FIG. 25, theconventional DV format is not able to record the data positioninformation (EPO in ATNF), etc. that are recorded in the presentinvention.

[0136] Returning to FIG. 22, the parity of 40 bits is arrangedsubsequent to the subcode data. This parity is added by the error codeand ID adding unit 5.

[0137] Subsequent to the subcode sector, the postamble (FIG. 7) isarranged. As with the preamble, the postamble is also recorded incombination of the pattern A and the pattern B shown in FIG. 8. Thepostamble has a length of 1500 bits when the head rotation issynchronized with 60×1000/1001 Hz, and has a length of 1375 bits when itis synchronized with 60 Hz.

[0138] The system data shown in FIGS. 14 and 15 will be described belowin more detail.

[0139] As described above, FIG. 14 shows the system data having a fixedlength along with the keyword number. For example, tape positioninformation (ATNF) corresponding to the keyword number 4 representssystem data having a fixed length, which is made up of an absoluteposition (ATN=Absolute Track Number) of 23 bits, a break flag (B flag)of 1 bit, and edit information of 8 bits.

[0140] The absolute position (ATN) indicates the distance (absoluteposition) of the track from the tape head.

[0141] The B flag is a flag set to “0” when the absolute position (e.g.,number) is continued, and set to “1” when the absolute position is notcontinued. By so setting the B flag, it is possible to assign themonotonously increasing numbers even in the case where data is recordedin mixed fashion and the absolute position is not continued. Thus, asearch can be accurately performed because of no return in the assignednumber.

[0142] The edit information comprises, as shown in FIG. 26, 8 bits ofb7-b0. An I flag is allocated to b7. The I flag is set to “1” wheninformation indicating a location to make a search (i.e., informationindicating a location that is designated at the time of recording) iscontained in the main sector corresponding to the subcode sector. Asearch position is detected based on the I flag.

[0143] A P flag is allocated to b5. The P flag is set to “1” whenrecording start video data for a still picture is contained in the mainsector corresponding to the subcode sector. A position at which a stillpicture is recorded is detected based on the P flag.

[0144] An EH flag is allocated to b4. The EH flag is set to “1” when anI or P picture is recorded in the main sector corresponding to thesubcode sector. Usually, editing, such as splicing between scenes on thetape, is started from an I or P picture. An edit position can betherefore detected based on the EH flag.

[0145] An edit picture header offset (EPO) is allocated to the remainingb3-b0. The EPO indicates the position of the main sector, to which thesubcode sector corresponds, in units of 16 tracks. The EPO will bedescribed in more detail with reference to FIG. 27. In an example ofFIG. 27, the value of EPO is 5 for a subcode sector in which the TTC hasa value 0, and this subcode sector is arranged in a predetermined trackin which the ECC number (number assigned in units of 16 tracks) is 6. Itis therefore understood that the main sector, to which the above subcodesector corresponds, is arranged in a track preceding the relevant track,in which the subcode sector is arranged, by the EPO value 5 ×16 tracks.Accordingly, it is possible to detect in which main sector an I or Ppicture serving as an edit point is actually recorded.

[0146] The above-mentioned system data is recorded in the main sectorand the subcode sector as described above.

[0147] The AUX data having a variable length, shown in FIG. 15, will bedescribed below. The AUX data is recorded only in the main sector.

[0148] For example, ECCTB (track block) corresponding to the keywordnumber 80 represents a packet including plural items of AUX data denotedby marks O in FIG. 28, including the length-fixed AUX data (such as thedata position information (ATNF) and TTC) shown in FIG. 14. The packetincludes, by way of example, as 3-byte audio mode, an audio frame size(3 bits), sample frequency (3 bits), etc., as shown in FIG. 29. Also,the packet includes, as video mode, a video rate (24 bits), etc., asshown in FIG. 30. Further, the packet includes, as DATA-H, informationindicating the type of picture, etc., as shown in FIG. 31.

[0149] The operation of the apparatus shown in FIG. 2 will be describedbelow. An HD video signal is inputted to the video data compressing unit1 together with search video data (thumbnail video data), in which it iscompressed by MP@HL or MP@H-14, for example. An audio signal is inputtedto the audio data compressing unit 2 and compressed therein. Subcodedata, AUX data, a header, etc. are supplied to the terminal 3 from thecontroller 13.

[0150] The switch 4 is controlled by the controller 13 to take in videodata (including search video data) outputted from the video datacompressing unit 1, audio data outputted from the audio data compressingunit 2, and system data inputted through the terminal 3 at thepredetermined timing, and then deliver those data to the error code andID adding unit 5 for merging thereof.

[0151] The error code and ID adding unit 5 adds an ID of 24 bits to eachof sync blocks of the main sector shown in FIG. 9. Also, the error codeand ID adding unit 5 calculates and adds a parity C1, shown in FIG. 9,for each sync block. Further, for 18 ones of 141 sync blocks, the errorcode and ID adding unit 5 adds a parity C2 in place of an SB header andmain data.

[0152] Furthermore, the error code and ID adding unit 5 calculates andadds an ID of 24 bits and a parity of 40 bits for each subcode syncblock of the subcode data, as shown in FIG. 22.

[0153] In addition, the error code and ID adding unit 5 holds data inamount corresponding to 16 tracks in the main sector and interleavesthose data among the 16 tracks.

[0154] The 24-25 converter 6 converts the data supplied from the errorcode and ID adding unit 5 in units of 24 bits into data in units of 25.As a result of this 24-25 conversion, components of the tracking pilotsignals having frequencies f1 and f2, shown in FIGS. 4 to 6, appear atenhanced levels.

[0155] The sync generator 7 adds a sync of 16 bits to each of the syncblocks of the main sector, as shown in FIG. 9. Also, the sync generator7 adds a sync of 16 bits to each of the subcode sync blocks of thesubcode sector, as shown in FIG. 22. Further, the sync generator 7generates the run patterns, shown in FIG. 8, for a preamble and apostamble.

[0156] More particularly, addition (merging) of those data is carriedout by the controller 13 changing over the switch 8 so that the dataoutputted from the sync generator 7 and the data outputted from the24-25 converter 6 are selected at the appropriate timing for supply tothe modulator 9.

[0157] The modulator 9 modulates the inputted data by a method adaptablefor the DV format, and outputs modulated data to the parallel/serialconverter 10. The parallel/serial converter 10 converts the inputtedparallel data into serial data, and supplies the serial data to therotary head 12 through the amplifier 11. The rotary head 12 records theinputted data on the magnetic tape 21.

[0158]FIG. 32 represents data, which has a GOP (Group of Picture)structure with N=15 (an I picture is arranged for each 15 pictures) andM=3 (a P picture is arranged for each 3 pictures), in a state where thedata is recorded on the magnetic tape 21 after being processed asdescribed above. More specifically, pictures in number indicated by avalue of M are set as one unit, and AUX data (denoted by U in FIG. 32)related to those pictures, audio data (denoted by A in FIG. 32)corresponding to those pictures, and AUX data (denoted by X in FIG. 32)related to the audio data are arranged together at the head of 16 tracksthat undergo interleaving. Subsequent to those data, one unit ofpictures (3 pictures in the illustrated example) is arranged.

[0159] In other words, since AUX data having a variable length isprepared and recorded in the main sector, it is possible to record suchAUX data together for each unit comprising a predetermined number ofpictures. As a result, the AUX data can be recorded with highefficiency.

[0160] Also, since the subcode sector records therein an EPO indicatingthe distance up to the main sector corresponding to the AUX data (datahaving a fixed length) recorded in that subcode sector, thecorresponding main sector can be easily detected.

[0161]FIG. 33 shows, by way of example, the case where the correspondingmain sector is detected by correcting an object value of the TTC basedon the EPO and then utilizing a corrected value.

[0162] The EPO can be determined by the following formula:

[0163] EPO=recording track number of subcode_TTC at editpoint/16-recording track number of main PIC_TTC corresponding tosubcode_TTC/16

[0164] In the above formula, {fraction (1/16)} is multiplied forconversion into the ECC block number. Also, since subcode_TTC recordsthe same data repeatedly for each 10 tracks, an offset value is obtainedin average frame units.

[0165] Accordingly, a target position can be detected in advance duringsearch travel (at the time when reaching the object TTC). In this case,however, history information for the offset is required (that is to say,the ECCTB must be prepared to shorten a pre-playback time).

[0166] Since the ECCTB (denoted by H in the drawings) is arranged at thehead of 16 tracks that undergo interleaving, a time of pre-playbackperformed for, e.g., splicing between scenes on the tape can beshortened. Stated otherwise, the AUX data required for pre-playback isinherently recorded in the subcode, but as described above, the subcodesector is arranged with a time lag relative to the corresponding mainsector. Referring to such AUX data therefore prolongs a pre-playbacktime correspondingly.

[0167]FIG. 34 shows collectively the AUX data (U) related to thepictures, the AUX data (X) related to the audio data, the ECCTB, and thedata contained in the subcode.

[0168]FIG. 35 shows another example of generating the EPO in a differentmanner. In this example, the EPO can be determined by the followingformula:

[0169] EPO=track head in ECC (=subcode_TTC—main PIC_TTC)

[0170] Accordingly, recording for slicing between scenes on the tape canbe performed without history information of the EPO. In this case,however, it is required in search travel to approach the TTC (targetposition), which has been resulted from the offset correction, afterreaching the TTC before the offset correction.

[0171] In the example of FIG. 35, the subcode sector in which the TTChas a value 0 is arranged in a track T0 of EEC6 (the EEC number being6). Stated otherwise, the corresponding main sector, which is arrangedin a track T0 of ECC0, can be detected by going back from the track T0of EEC6 by 9×16 tracks. Additionally, since the subcode sector arrangedin each track of ECC6 corresponds to the main sector where an I pictureis recorded, the EH header for the subcode sector is set to “1”.

[0172]FIG. 36 shows one example of construction of a playback system forreproducing the data recorded on the magnetic tape 21 as describedabove.

[0173] The rotary head 12 reproduces the data recorded on the magnetictape 21 and outputs the reproduced data to an amplifier 41. Theamplifier 41 amplifies and supplies the inputted signal to an A/Dconverter 42. The A/D converter 42 converts the inputted analog signalinto a digital signal and supplies it to a demodulator 43. Thedemodulator 43 demodulates the data supplied from the A/D converter 42by a method corresponding to the modulation method used in the modulator9 of FIG. 2.

[0174] From the data demodulated by the demodulator 43, a sync detector44 detects the sync for each sync block of the main sector shown in FIG.9 and the sync for each subcode sync block of the subcode sector shownin FIG. 22 for supply to an error correcting and ID detecting unit 46. A25-24 converter 45 converts the data supplied from the demodulator 43 inunits of 25 bits into data in units of 24 bits corresponding to theconversion made in the 24-25 converter 6 of FIG. 2, and outputsconverted data to the error correcting and ID detecting unit 46.

[0175] The error correcting and ID detecting unit 46 executes an errorcorrecting process, an ID detecting process, and an interleaving processbased on the syncs inputted from the sync detector 44.

[0176] A switch 47 is controlled by the controller 13 and outputs, ofdata outputted from the error correcting and ID detecting unit 46, videodata (including search video data) to a video data decompressing unit48, audio data to an audio data decompressing unit 49, and system data,such as subcode data and AUX data, to the controller 13 through aterminal 50.

[0177] The video data decompressing unit 48 decompresses the inputtedvideo data and outputs it as an analog HD video signal after D/Aconversion. The audio data decompressing unit 49 decompresses theinputted audio data and outputs it as an analog audio signal after D/Aconversion.

[0178] The operation of the playback system thus constructed will bedescribed below. The rotary head 12 reproduces the data recorded on themagnetic tape 21 in the form shown in FIG. 32. The reproduced data isamplified by the amplifier 41 and then supplied to the A/D converter 42.Digital data converted from the analog data by the A/D converter 42 isinputted to and demodulated by the demodulator 43.

[0179] The 25-24 converter 45 converts the demodulated data from thedemodulator 43 in units of 25 bits into data in units of 24, and outputsthe converted data to the error correcting and ID detecting unit 46.

[0180] From the data outputted from the demodulator 43, the syncdetector 44 detects each sync of the main sector shown in FIG. 9 andeach sync of the subcode sector shown in FIG. 22 for supply to the errorcorrecting and ID detecting unit 46. The error correcting and IDdetecting unit 46 stores data in amount corresponding to 16 tracks andexecutes the interleaving process, and also executes the errorcorrecting process using each parity C1, C2 of the main sector shown inFIG. 9. Further, the error correcting and ID detecting unit 46 detectseach SB header of the main sector, and determines which one of audiodata, video data, AUX data, search video data, etc. is contained in eachsync block.

[0181] In addition, the error correcting and ID detecting unit 46executes the error correcting process of the subcode data using eachparity of the subcode sector shown in FIG. 22, and detects a packetkeyword (header) of the AUX data to determine the contents of thesubcode data. It is hence determined whether the subcode data representsthe track number or the time code number.

[0182] Based on the SB header detected by the error correcting and IDdetecting unit 46, the switch 47 supplies both the video data and thesearch video data to the video data decompressing unit 48. The videodata decompressing unit 48 decompresses the inputted data by a methodcorresponding to the compression method used in the video datacompressing unit 1 of FIG. 2, and then outputs the decompressed data asa video signal.

[0183] Also, the switch 47 outputs the audio data to the audio datadecompressing unit 49. The audio data decompressing unit 49 decompressesthe inputted audio data by a method corresponding to the compressionmethod used in the audio data compressing unit 2 of FIG. 2, and thenoutputs the decompressed data as an audio signal.

[0184] Further, the switch 47 outputs the AUX data, the subcode data,etc. delivered from the error correcting and ID detecting unit 46 to thecontroller 13 through the terminal 50.

[0185] Thus, the data, including pictures and audio data, recorded inthe form shown in FIG. 32 is decompressed.

[0186] While the above description has been made, by way of example, inconnection with the case of decompressing pictures and audio datarecorded on the magnetic tape 21, the decompressed data may bemultiplexed to produce MPEG data.

[0187] A sequence of the above-described processing can be executed withhardware, but it may also be executed with software. When executing asequence of the above-described processing with software, a programconstituting the software is installed from a storage medium to, e.g., acomputer incorporated in dedicated hardware, or a universal personalcomputer capable of executing various functions when various programsare installed therein.

[0188] As shown in FIGS. 2 and 36, such a storage medium may be in theform of package media, such as a magnetic disk 31 (including a floppydisk), an optical disk 32 (including CDROM (Compact Disk-Read OnlyMemory) and DVD (Digital Versatile Disk)), a magneto-optical disk 33(including MD (Mini-Disk)), and a semiconductor memory 34, which storethe program therein and are distributed separately from a body of themagnetic tape recording/playback apparatus to provide the program to auser. In addition, the storage medium may be a ROM, a hard disk or thelike, which stores the program therein and is provided to a user in astate assembled in the apparatus body beforehand.

[0189] It is to be noted that the steps describing the program stored ina storage medium can be processed in time series following the sequencedescribed in the specification, but may also be processed in parallel orindividually without being always restricted to the time-serialprocessing.

[0190] With the magnetic tape recording apparatus, the magnetic taperecording method, and the storage medium product storing thecomputer-readable program according to the present invention, asdescribed above, one of video data, audio data or search data andauxiliary data having a variable length and related to any of those datais acquired as first group data, and data containing a subcode relatedto the first group data is acquired as second group data. The firstgroup data and the second group data are merged such that the first andsecond group data are continuously arranged on tracks of a magnetic tapewithout being spaced away from each other. Merged data is supplied forrecording on the magnetic tape. Therefore, data having a large amount ofinformation, represented by data of an HD video signal, can be recordedon the magnetic tape in a digital manner.

[0191] With the format for a magnetic tape according to the presentinvention, since the first group data and the second group data aremerged such that the first and second group data are continuouslyarranged on tracks of the magnetic tape without being spaced away fromeach other, a magnetic tape can be realized which records data requiringa large capacity as represented by data of an HD video signal.

[0192] With the magnetic tape playback apparatus, the magnetic tapeplayback method, and the storage medium product storing thecomputer-readable program according to the present invention, theauxiliary data is acquired, as first group data, from data reproducedfrom a magnetic tape with a rotary head, and the data reproduced fromthe magnetic tape is processed based on the acquired auxiliary data. TheHD video data can be therefore played back with certainty.

What is claimed is:
 1. A magnetic tape recording apparatus for recordingdigital data on a magnetic tape with a rotary head, said apparatuscomprising: first acquiring means for acquiring video data, audio dataor search data; second acquiring means for acquiring auxiliary datahaving a variable length and related to the data acquired by said firstacquiring means; selecting means for selecting, as first group data, oneof the data acquired by said first acquiring means and the data acquiredby said second acquiring means; third acquiring means for acquiringsecond group data containing a subcode related to said first group data;merging means for merging said first group data and said second groupdata such that said first group data and said second group data arecontinuously arranged on tracks of said magnetic tape without beingspaced away from each other; and supplying means for supplying datamerged by said merging means to said rotary head to record the mergeddata on said magnetic tape.
 2. A magnetic tape recording apparatusaccording to claim 1, wherein said first acquiring means acquires, assaid first group data, the video data in edit units.
 3. A magnetic taperecording apparatus according to claim 1, wherein said second acquiringmeans acquires, as said second group data, auxiliary data related to theaudio data and auxiliary data related to the video data; and saidmerging means merges the auxiliary data related to the audio data, theaudio data, the auxiliary data related to the video data, and the videodata to be arranged in this order.
 4. A magnetic tape recordingapparatus according to claim 1, wherein said second acquiring meansfurther acquires auxiliary data required for pre-playback; and saidmerging means merges the auxiliary data required for pre-playback to bearranged at the head of an edit unit of the video data.
 5. A magnetictape recording apparatus according to claim 4, wherein the auxiliarydata required for pre-playback includes the contents recorded in asubcode sector.
 6. A magnetic tape recording method used in a magnetictape recording apparatus for recording digital data on a magnetic tapewith a rotary head, said method comprising the steps of: a firstacquiring step of acquiring video data, audio data or search data; asecond acquiring step of acquiring auxiliary data having a variablelength and related to the data acquired by processing in said firstacquiring step; a selecting step of selecting, as first group data, oneof the data acquired by processing in said first acquiring step and thedata acquired by processing in said second acquiring step; a thirdacquiring step of acquiring second group data containing a subcoderelated to said first group data; a merging step of merging said firstgroup data and said second group data such that said first group dataand said second group data are continuously arranged on tracks of saidmagnetic tape without being spaced away from each other; and a supplyingstep of supplying data merged by processing in said merging step to saidrotary head to record the merged data on said magnetic tape.
 7. Astorage medium product storing a computer-readable program comprisingthe steps of: a first acquiring step of acquiring video data, audio dataor search data; a second acquiring step of acquiring auxiliary datahaving a variable length and related to the data acquired by processingin said first acquiring step; a selecting step of selecting, as firstgroup data, one of the data acquired by processing in said firstacquiring step and the data acquired by processing in said secondacquiring step; a third acquiring step of acquiring second group datacontaining a subcode related to said first group data; a merging step ofmerging said first group data and said second group data such that saidfirst group data and said second group data are continuously arranged ontracks of said magnetic tape without being spaced away from each other;and a supplying step of supplying data merged by processing in saidmerging step to said rotary head to record the merged data on saidmagnetic tape.
 8. A format for a magnetic tape on which digital data isrecorded with a rotary head, wherein: first group data comprising videodata, audio data or search data, or comprising auxiliary data having avariable length and related to the video data, the audio data or thesearch data, and second group data containing a subcode related to thevideo data, the audio data or the search data are recorded such thatsaid first group data and said second group data are continuouslyarranged on tracks of said magnetic tape without being spaced away fromeach other.
 9. A magnetic tape playback apparatus for playing back, witha rotary head, a magnetic tape on which first group data comprisingcompressed high-definition or standard-definition video data, audio dataor search data, or comprising auxiliary data having a variable lengthand related to the video data, the audio data or the search data, andsecond group data containing a subcode related to said first group dataare recorded such that said first group data and said second group dataare continuously arranged on tracks without being spaced away from eachother, said apparatus comprising: acquiring means for acquiring theauxiliary data, as said first group data, or said second group data fromdata reproduced from said magnetic tape with said rotary head; anddecompressing means for decompressing the compressed high-definitionvideo data, which is contained in the data reproduced from said magnetictape with said rotary head, by using the auxiliary data or said secondgroup data acquired by said acquiring means.
 10. A magnetic tapeplayback method used in a magnetic tape playback apparatus for playingback, with a rotary head, a magnetic tape on which first group datacomprising compressed high-definition or standard-definition video data,audio data or search data, or comprising auxiliary data having avariable length and related to the video data, the audio data or thesearch data, and second group data containing a subcode related to saidfirst group data are recorded such that said first group data and saidsecond group data are continuously arranged on tracks without beingspaced away from each other, said method comprising the steps of: anacquiring step of acquiring the auxiliary data, as said first groupdata, or said second group data from data reproduced from said magnetictape with said rotary head; and a decompressing step of decompressingthe compressed high-definition video data, which is contained in thedata reproduced from said magnetic tape with said rotary head, by usingthe auxiliary data or said second group data acquired by processing insaid acquiring step.
 11. A storage medium product storing acomputer-readable program for controlling a magnetic tape playbackapparatus for playing back, with a rotary head, a magnetic tape on whichfirst group data comprising compressed high-definition orstandard-definition video data, audio data or search data, or comprisingauxiliary data having a variable length and related to the video data,the audio data or the search data, and second group data containing asubcode related to said first group data are recorded such that saidfirst group data and said second group data are continuously arranged ontracks without being spaced away from each other, said programcomprising the steps of: an acquiring step of acquiring the auxiliarydata, as said first group data, or said second group data from datareproduced from said magnetic tape with said rotary head; and adecompressing step of decompressing the compressed high-definition videodata, which is contained in the data reproduced from said magnetic tapewith said rotary head, by using the auxiliary data or said second groupdata acquired by processing in said acquiring step.